Method for assembling tone hole covering in wood-wind musical instrument

ABSTRACT

A process for assembling a tone hole covering assembly comprises interposing an uncured thermosetting resin between the inner bottom surface of the cup and the pad, and heating and curing the resin while the pad is kept engaged with the tone hole socket of the instrument body in a predetermined airtight condition. The airtightness between the pad and the tone hole socket can be secured without the necessity for repeatedly adjusting the relative position of the pad and the cup.

United States Patent 1 [111 3,767,506 Kawakami Oct. 23, 1973 [54] METHOD FOR ASSEMBLING TONE HOLE 1,786,833 12/1930 Pytch 84/384 COVERING IN WOOD-WIND MUSICAL INSTRUMENT inventor: Genichi Kawakami, Hamakita,

Japan Nippon Gakki Seizo Kabushiki Kaisha, Hamamatsu-shi, Shizuoka-ken, Japan Filed: Jan. 6, 1972 Appl. No.: 215,892

Related US. Application Data Continuation of Ser. No. 46,877, June 17, 1970, abandoned.

Assignee:

US. Cl 156/293, 84/380, 84/382,

84/384, 156/313 Int. Cl. C09j 5/06 Field of Search 156/293, 313;

References Cited UNITED STATES PATENTS 1/1969 Greenleaf et al. 84/380 OTHER PUBLICATIONS Armstead, B. H. & Begeman, M. L., Manufacturing Processes, N.Y., Wiley, 1965, pp. 264-271.

Van Vlack, L. H. Elements of Materials Science Reading, Mass, Addison-Wesley, 1964 p. 189.

Primary Examiner-Alfred L. Leavitt Assistant Examiner-Caleb Weston Att0rneyFlynn & Frishauf [57] ABSTRACT 14 Claims, 4 Drawing Figures 1 METHOD FOR ASSEMBLING TONE I-IOLE COVERING IN WOOD-WIND MUSICAL INSTRUMENT This is a continuation of US. Pat. application Ser. No. 46,877, filed Jun. 17, 1970 now abandoned.

This invention relates to a process for assembling a tone hole covering assembly for wood-wind musical instruments.

Usually, the tone hole covering assembly for a Woodwind instrument, such as a flute, engages a tone hole socket formed in the instrument in an open and closed relationship, by rotatably operating a key cup connected to a hinge through an arm extending from the cup, which hinge is pivoted to the body of the instrument. It is known that the airtightness of the pad with respect to the tone hole socket which is obtained when the pad engages the tone hole socket greatly influences the stability of the musical tone, especially at the bass tone region. Frequently, the pad does not engage the tone hole socket in a desired condition due to a lack of precision in positioning the key cup, the hinge and the tone hole socket and in the production of accessory parts. This calls for troublesome and inaccurate adjustments of removing the cup together with the hinge and placing a suitable number of spacer sheets between the bottom surface of the cup and the pad to control the inclination of the contact surface of the pad. Such adjusting operation requires high skill and is timeconsuming, thus lowering the productivity.

The object of the invention is to eliminate the drawbacks described above and to provide a tone hole covering assembly and a process for assembling the same ensuring a positive and predetermined airtightness without the need of any later adjusting operation. The object is attained by securing the pad to the key cup, interposing an uncured thermosetting resin impregnated sheet therebetween, holding the pad in engagement with a tone hole socket of the instrument, and curing the thermosetting resin.

This invention can be more fully understood from the following detailed description when taken in connection with the accompanying drawing, in which:

FIG. I is a perspective view of a tone hole covering assembly embodying this invention;

, FIG. 2 is a front view, partly in section, of the assemy;

FIG. 3 is a view similar to FIG. 2, illustrating a modification of the invention; and

FIG. 4 is a vertical cross section of an element of the assembly shown in FIG. 3.

The tone hole covering assembly for a wood-wind musical instrument as shown in FIGS. 1 and 2 comprises a key cup 1 1 having therein a central seat 12 with internal threads, a doughnut-shaped pad of felt or other suitable materials 13 received in the cup 11 about the threaded seat 12, a base sheet 14 of a ring shape adhered on the surface of the pad which faces the inner bottom surface of the cup 11, and a fish skin 15 covering the pad and the base sheet.

The cup 11 is provided with an outwardly extending arm Ila to which a key hinge 11b is secured. The key hinge 11b is pivotally connected to the tubular body of a woodwind instrument by means of a journal not shown, and is rotatably operated. When the key hinge 11b is in its assembled state, the circular edge 17a of a tone hole socket 17 formed in the tubular body 20 en- 2 gages the outer surface of the pad 13 including the fish skin 15.

Between the inner bottom surface of the cup 11 and the corresponding surface of the pad 13 is interposed a cured thermosetting resin 16 such as cured polyester, epoxy or silicon resin. The thermosetting resin may, before it is cured, be mixed with a filler or loading agent such as calcium carbonate, and further with a reinforcement or strengthening material such as glass fiber, natural or synthetic fiber, yarn, or corky material, which may be either powder, grains or chips. One example of such mixture is as follows.

Polyester resin parts Calcium carbonate 230 parts Glass fiber 42 parts Benzoyl peroxide (as hardening agent) 4 parts The process for assembling the tone hole covering assembly of this invention, as for example, employing the above-mentioned mixture will be explained hereinafter. Said mixture forming a kind of pre-mix is first placed into the cup 11 by a proper quantity. The pad 13 is then fixed in the cup 11, backed by the mixture, as by threadedly engaging a screw 19 with the threaded seat 12 through a washer 18, which serves to press the inner edge of the pad 13 against the inner bottom surface of the cup 11. As a next step, the pad is pressed against the circular edge 17a of the tone hole socket 17 with proper pressure and kept in engaged relationship with the latter. The mixture is thereafter cured by heat treatment, for example, at 100 to C for 30 to 60 minutes.

According to the process of this invention, the pad 13 is kept in forcedly engaged relationship with the circular edge 17a with the uncured thermosetting resin 16 being interposed between the inner bottom surface of the cup 11 and the pad 13, and the resin 16 in a soft condition is so formed and then cured in the cup as to permit the contact surface of the pad 13 to tightly engage the tone hole socket 17 and as to allow the pad 13 to close the tone hole socket 17 to such an extent as to maintain required airtightness. The pad 13 is thus suitably positioned and fitted to the tone hole socket in its assembled state, and no further subsequent adjustment will be necessary.

In a modification shown in FIGS. 3 and 4, a doughnut-shaped flexible spacer 21 in which thermosetting resin is pre-impregnated is employed. The spacer 21 may be made ofa strengthening material such as paper, felt, non-woven fabric or the like in which a thermosetting resin, such as polyester, phenol, epoxy, silicon or the like is preimpregnated. An example of the impregnates is as follows.

Polyester 100 parts Magnesium oxide (as condensing agent) 2 parts Zinc stearate (as parting agent) 3 parts Benzoyl peroxide (as hardening agent) l part Stylene monomer (as cross linking agent) 15 parts The process for assembling the tone hole covering assembly using the aforesaid spacer 21 will be explained below.

A sheet of paper, for example, is soaked with a thermosetting resin, coated on both surfaces with separate sheets of polyethylene each having a thickness of say 0.03 mm so as to form a three-layer structure, and then dried at 60 C for 15 minutes. The sheet of paper thus treated becomes a kind of pre-preg. The sheet is cut into a proper shape like a doughnut-shape as shown in FIG. 4, which constitutes the spacer 21 consisting of a pre-impregnated layer 21a and two separate layers 21b andv 21c of polyethylene coated on' both surfaces thereof. The spacer 21 whose shape conforms to the shape of the pad is placed into the cup 11 and the pad 13 is then laid on the spacer 21 and secured in the cup as by threadedly engaging the screw 19 with the seat 12 through the washer 18.

The cup 11 carrying therein the spacer 21 and the pad 13 is assembled with the body of a musical instrument 20 with the outer surface of the pad 13 pressedly engaged with the edge 17a of the tone hole socket l7, and kept in engaged relationship with each other, whereby the spacer 21 is deformed in such a manner that the pad 13 and the tone hole socket 17 are held in an airtight relationship with each other. While the spacer is held deformed, it is subjected to heat treatment at 100 to 120 C for to 60 minutes, with the result that the spacer is cured in its deformed state without the necessity of any further adjustment of the pad'l3.

The sheet of paper above described is coated with the separate sheets of polyethylene so as to facilitate the releasing of the spacer 21 from the inner bottom surfaceof the cup 11 after the thermosetting resin impregnated'in the spacer 21 is cured, but the polyethylene sheets may be omitted.

According to this invention, the pad can be fitted to the tone hole socket with positive and required airtightness without the need of repeatedly adjusting the position of the pad at the time of-the assembling operation, so that the assembling operation can be greatly simplitied and the efficiency of production can be greatly improved.

What is claimed is:

1. A process for assembling a tone hole covering assembly for a wood-wind musical instrument having a cup and a pad housed in the cup and for opening or closing a tone hole socket formed on the body of the instrument comprising steps of:

soaking'a layer of sheet-like strengthening material in a thermosetting resinous solution so that said material is coated. with a thermosetting resin;

drying said'coated material so that it is brought into a pre-preg state;

then cutting said dried material into a shape conforming to the shape of the pad;

placing said shaped :material into the cup;

laying the pad on said shaped material and placing the pad in the cup with said shaped material interposed between the pad and the cup;

pressing the pad to the edge of the tone hole socket so that the pad is engaged with the edge of the tone hole socket in a predetermined airtight relationship; and then heating and then curing the thermosetting resin while pressing the pad in engaged relationship with the edge of the socket.

2. The process as claimed in claim 1, wherein said thermosetting resin is heated during said heating and curing step at a temperature of to C for 30 to 60 minutes.

3. The process as claimed in claim 1, further comprising a step of coating said strengthening material with polyethylene sheets after said material is soaked into the thermosetting resinous solution.

4. The process as claimed in claim 1, wherein said strengthening material is a sheet of paper.

5. The process as claimed in claim 1 wherein said strengthening material is generally doughnut-shaped.

6. The process as claimed in claim 1 wherein said step of securing the pad in the cup comprises passing a screw member through said pad and threadably engaging said screw member with said cup.

7. The process as claimed in claim 1 wherein the steps prior to pressing the pad to the edge of the tone hole socket are performed prior to assembling said cup to the musical instrument, and comprising the step of assembling said cup carrying said pad and shaped material to said musical instrument prior to pressing the pad to the edge of the tone hole socket.

8. The process as claimed in claim 1, wherein said strengthening material is a sheet of felt.

9. The process as claimed in claim 1 wherein said strengthening material is a sheet of non-woven fabric.

10. The process as claimed in claim 1, wherein said strengthening material is dried at a temperature of about 60 C for about 15 minutes.

11. The process as claimed in claim 10, wherein said thermosetting resin is heated at a temperature of 100 to 120 C for 30 to 60 minutes.

12. The process as claimed in claim 1 comprising covering at least one side of said coated layer of strengthening material with a thin sheet of polyethylene prior to said drying step to form a multi-layer structure.

13. The process as claimed in claim 12 comprising covering both sides of said coated layer of strengthening material with thin sheets of polyethylene before said drying step to form a three-layer structure.

14. The process as claimed in claim 13 wherein said covering step comprises covering said coated layer of strengthening material with separate respective thin sheets of polyethylene. 

2. The process as claimed in claim 1, wherein said thermosetting resin is heated during said heating and curing step at a temperature of 100* to 120* C for 30 to 60 minutes.
 3. The process as claimed in claim 1, further comprising a step of coating said strengthening material with polyethylene sheets after said material is soaked into the thermosetting resinous solution.
 4. The process as claimed in claim 1, wherein said strengthening material is a sheet of paper.
 5. The process as claimed in claim 1 wherein said strengthening material is generally doughnut-shaped.
 6. The process as claimed in claim 1 wherein said step of securing the pad in the cup comprises passing a screw member through said pad and threadably engaging said screw member with said cup.
 7. The process as claimed in claim 1 wherein the steps prior to pressing the pad to the edge of the tone hole socket are performed prior to assembling said cup to the musical instrument, and comprising the step of assembling said cup carrying said pad and shaped material to said musical instrument prior to pressing the pad to the edge of the tone hole socket.
 8. The process as claimed in claim 1, wherein said strengthening material is a sheet of felt.
 9. The process as claimed in claim 1 wherein said strengthening material is a sheet of non-woven fabric.
 10. The process as claimed in claim 1, wherein said strengthening material is dried at a temperature of about 60* C for about 15 minutes.
 11. The process as claimed in claim 10, wherein said thermosetting resin is heated at a temperature of 100* to 120* C for 30 to 60 minutes.
 12. The process as claimed in claim 1 comprising covering at least one side of said coated layer of strengthening material with a thin sheet of polyethylene prior to said drying step to form a multi-layer structure.
 13. The process as claimed in claim 12 comprising covering both sides of said coated layer of strengthening material with thin sheets of polyethylene before said drying step to form a three-layer structure.
 14. The process as claimed in claim 13 wherein said covering step comprises covering said coated layer of strengthening material with separate respective thin sheets of polyethylene. 